Pilot Investigation

Abstract

1577 PURPOSE: To evaluate sex specific effects of abdominal maneuvers on lower extremity energetics during single leg landings. METHODS: 12 male (24.0 ± 3.4 yrs, 177.1 ± 6.9 cm, 85.8 ± 16.7 kg) and 12 female (21.9 ± 2.3 yrs, 166.3 ± 4.4 cm, 62.2 ± 4.4 kg) recreationally active subjects reported for a familiarization session followed by two days of data collection. The familiarization session required subjects to perform a single leg landing task from a .3m box. Subjects were then randomly assigned to one of three groups: control, abdominal hollowing (AH), or pelvic tilting (PT). Subjects assigned to the treatment groups were then instructed in their respective abdominal maneuvers and were instructed to perform the abdominal maneuver throughout the duration of the task. On days 2 & 3, subjects performed five single leg landings respective to their assigned group while kinematic, kinetic, and abdominal circumference measures were collected. RESULTS: Kinematics demonstrated consistent pelvic positioning during landing for all subjects in the PT group across days (ICC = .90, SEM = 0.7°). Circumference measures were moderately consistent (ICC = .53, SEM = 0.4cm) for all subjects in the AH condition suggesting subjects could effectively maintain a decreased abdominal circumference during landing. Kinetic analyses revealed no significant results. However, relative knee work absorption effect sizes comparing the control to each abdominal maneuver condition revealed large treatment effects for females (AH = 1.33, PT = 1.22) but not males (AH = .07, PT = .18) (Table 1). CONCLUSION: Due to the small N used, these effect sizes provide preliminary evidence to consider sex when evaluating the influence of abdominal maneuvering on lower extremity energetics. These observations support previous research stating females demonstrate higher knee work absorption during landing. These pilot results suggest male and female lower extremity energetics differ when performing abdominal maneuvers during single leg landings, and support the need for further research in this area.Table 1: Relative Knee Work Absorption (% of Total)